Now, solar cells produced from sunlight
Posted on Apr 04 2014 | IANS
New York, April 4 : Solar cells tap energy from sun, but what if these solar cells themselves can be produced from sunlight?
In a recent advance in solar energy, researchers have discovered a way to tap the sun to directly produce solar energy materials.
Cheaper and slimmer than conventional silicon cells, these could soon be used as coatings in buildings to produce energy.
This breakthrough by chemical engineers at Oregon State University could soon reduce the cost of solar energy, expedite production processes and make the sun almost a "one-stop shop" that produces both the materials for solar devices and the eternal energy to power them.
"This approach should work and is very environmentally conscious," said Chih-Hung Chang, a professor of chemical engineering at Oregon State University.
Several aspects of this system should continue to reduce the cost of solar energy, and when widely used, our carbon footprint, Chang added.
The work is based on the use of a "continuous flow" microreactor to produce nanoparticle inks that make solar cells by printing.
In this process, simulated sunlight is focused on the solar microreactor to rapidly heat it.
"Our system can synthesise solar energy materials in minutes compared to other processes that might take 30 minutes to two hours," Chang said.
"This gain in operation speed can lower cost."
In these experiments, the solar materials were made with copper indium diselenide, but to lower material costs it might also be possible to use a compound such as copper zinc tin sulfide, Chang said.
The chalcogenide-based, thin film solar cells have already returned a fairly high solar energy conversion efficiency of about 20 percent in the laboratory, researchers said, while costing less than silicon technology.
Further improvements in efficiency should be possible, they said.
The findings were published in the journal RSC Advances.